The BFS chipset of Fore Systems stripes data across multiple fabrics. The striping function is identical for both OC48 and OC192 ports. The parity generation function (calculation of the data bits for the spare fabric) requires data from multiple stripers. The derivation of the parity functions has been defined to optimize the chip to chip communication required for both encoding and decoding of the parity information on the BFS port cards and to allow for traffic to be sent between OC48 and OC192 ports.
The present invention allows a design to support both OC48 and OC192 link speed with minimal overhead in the function which calculates parity and does not require knowledge of all bits for OC192 operation. This allows the striping function to be implemented in a smaller, cheaper package. Additionally, it allows chip placement to be varied in optimizing the board level wiring between the striper function and the backplane, which is necessary to make the system implementable.